TST: Use more pytest fixtures (pandas-dev#53679)

* TST: Use more pytest fixtures

* Fix sql fixture

* More test fixtures

pandas/tests/interchange/test_impl.py

@@ -16,47 +16,31 @@
 )
 from pandas.core.interchange.from_dataframe import from_dataframe
 
-test_data_categorical = {
-    "ordered": pd.Categorical(list("testdata") * 30, ordered=True),
-    "unordered": pd.Categorical(list("testdata") * 30, ordered=False),
-}
 
-NCOLS, NROWS = 100, 200
-
-
-def _make_data(make_one):
+@pytest.fixture
+def data_categorical():
     return {
-        f"col{int((i - NCOLS / 2) % NCOLS + 1)}": [make_one() for _ in range(NROWS)]
-        for i in range(NCOLS)
+        "ordered": pd.Categorical(list("testdata") * 30, ordered=True),
+        "unordered": pd.Categorical(list("testdata") * 30, ordered=False),
     }
 
 
-int_data = _make_data(lambda: random.randint(-100, 100))
-uint_data = _make_data(lambda: random.randint(1, 100))
-bool_data = _make_data(lambda: random.choice([True, False]))
-float_data = _make_data(lambda: random.random())
-datetime_data = _make_data(
-    lambda: datetime(
-        year=random.randint(1900, 2100),
-        month=random.randint(1, 12),
-        day=random.randint(1, 20),
-    )
-)
-
-string_data = {
-    "separator data": [
-        "abC|DeF,Hik",
-        "234,3245.67",
-        "gSaf,qWer|Gre",
-        "asd3,4sad|",
-        np.NaN,
-    ]
-}
+@pytest.fixture
+def string_data():
+    return {
+        "separator data": [
+            "abC|DeF,Hik",
+            "234,3245.67",
+            "gSaf,qWer|Gre",
+            "asd3,4sad|",
+            np.NaN,
+        ]
+    }
 
 
 @pytest.mark.parametrize("data", [("ordered", True), ("unordered", False)])
-def test_categorical_dtype(data):
-    df = pd.DataFrame({"A": (test_data_categorical[data[0]])})
+def test_categorical_dtype(data, data_categorical):
+    df = pd.DataFrame({"A": (data_categorical[data[0]])})
 
     col = df.__dataframe__().get_column_by_name("A")
     assert col.dtype[0] == DtypeKind.CATEGORICAL
@@ -143,9 +127,25 @@ def test_bitmasks_pyarrow(offset, length, expected_values):
 
 
 @pytest.mark.parametrize(
-    "data", [int_data, uint_data, float_data, bool_data, datetime_data]
+    "data",
+    [
+        lambda: random.randint(-100, 100),
+        lambda: random.randint(1, 100),
+        lambda: random.random(),
+        lambda: random.choice([True, False]),
+        lambda: datetime(
+            year=random.randint(1900, 2100),
+            month=random.randint(1, 12),
+            day=random.randint(1, 20),
+        ),
+    ],
 )
 def test_dataframe(data):
+    NCOLS, NROWS = 10, 20
+    data = {
+        f"col{int((i - NCOLS / 2) % NCOLS + 1)}": [data() for _ in range(NROWS)]
+        for i in range(NCOLS)
+    }
     df = pd.DataFrame(data)
 
     df2 = df.__dataframe__()
@@ -227,7 +227,7 @@ def test_mixed_missing():
         assert df2.get_column_by_name(col_name).null_count == 2
 
 
-def test_string():
+def test_string(string_data):
     test_str_data = string_data["separator data"] + [""]
     df = pd.DataFrame({"A": test_str_data})
     col = df.__dataframe__().get_column_by_name("A")

pandas/tests/interchange/test_spec_conformance.py

@@ -7,6 +7,17 @@
 
 import pytest
 
+import pandas as pd
+
+
+@pytest.fixture
+def df_from_dict():
+    def maker(dct, is_categorical=False):
+        df = pd.DataFrame(dct)
+        return df.astype("category") if is_categorical else df
+
+    return maker
+
 
 @pytest.mark.parametrize(
     "test_data",

pandas/tests/io/excel/test_xlrd.py

@@ -10,10 +10,8 @@
 
 xlrd = pytest.importorskip("xlrd")
 
-exts = [".xls"]
 
-
-@pytest.fixture(params=exts)
+@pytest.fixture(params=[".xls"])
 def read_ext_xlrd(request):
     """
     Valid extensions for reading Excel files with xlrd.

pandas/tests/io/formats/style/test_html.py

@@ -15,8 +15,12 @@
 jinja2 = pytest.importorskip("jinja2")
 from pandas.io.formats.style import Styler
 
-loader = jinja2.PackageLoader("pandas", "io/formats/templates")
-env = jinja2.Environment(loader=loader, trim_blocks=True)
+
+@pytest.fixture
+def env():
+    loader = jinja2.PackageLoader("pandas", "io/formats/templates")
+    env = jinja2.Environment(loader=loader, trim_blocks=True)
+    return env
 
 
 @pytest.fixture
@@ -31,12 +35,12 @@ def styler_mi():
 
 
 @pytest.fixture
-def tpl_style():
+def tpl_style(env):
     return env.get_template("html_style.tpl")
 
 
 @pytest.fixture
-def tpl_table():
+def tpl_table(env):
     return env.get_template("html_table.tpl")
 
 

pandas/tests/io/formats/test_format.py

@@ -24,11 +24,6 @@
 
 from pandas._config import config
 
-from pandas.compat import (
-    IS64,
-    is_platform_windows,
-)
-
 import pandas as pd
 from pandas import (
     DataFrame,
@@ -48,8 +43,6 @@
 from pandas.io.formats import printing
 import pandas.io.formats.format as fmt
 
-use_32bit_repr = is_platform_windows() or not IS64
-
 
 def get_local_am_pm():
     """Return the AM and PM strings returned by strftime in current locale."""

pandas/tests/io/parser/usecols/test_parse_dates.py

@@ -13,15 +13,6 @@
 )
 import pandas._testing as tm
 
-_msg_validate_usecols_arg = (
-    "'usecols' must either be list-like "
-    "of all strings, all unicode, all "
-    "integers or a callable."
-)
-_msg_validate_usecols_names = (
-    "Usecols do not match columns, columns expected but not found: {0}"
-)
-
 # TODO(1.4): Change these to xfails whenever parse_dates support(which was
 # intentionally disable to keep small PR sizes) is added back
 pytestmark = pytest.mark.usefixtures("pyarrow_skip")

pandas/tests/io/parser/usecols/test_strings.py

@@ -9,15 +9,6 @@
 from pandas import DataFrame
 import pandas._testing as tm
 
-_msg_validate_usecols_arg = (
-    "'usecols' must either be list-like "
-    "of all strings, all unicode, all "
-    "integers or a callable."
-)
-_msg_validate_usecols_names = (
-    "Usecols do not match columns, columns expected but not found: {0}"
-)
-
 
 def test_usecols_with_unicode_strings(all_parsers):
     # see gh-13219
@@ -70,7 +61,11 @@ def test_usecols_with_mixed_encoding_strings(all_parsers, usecols):
 2.613230982,2,False,b
 3.568935038,7,False,a"""
     parser = all_parsers
-
+    _msg_validate_usecols_arg = (
+        "'usecols' must either be list-like "
+        "of all strings, all unicode, all "
+        "integers or a callable."
+    )
     with pytest.raises(ValueError, match=_msg_validate_usecols_arg):
         parser.read_csv(StringIO(data), usecols=usecols)
 

pandas/tests/io/pytables/test_round_trip.py

@@ -26,9 +26,6 @@
 )
 from pandas.util import _test_decorators as td
 
-_default_compressor = "blosc"
-
-
 pytestmark = pytest.mark.single_cpu
 
 
@@ -479,7 +476,7 @@ def _make_one():
 def _check_roundtrip(obj, comparator, path, compression=False, **kwargs):
     options = {}
     if compression:
-        options["complib"] = _default_compressor
+        options["complib"] = "blosc"
 
     with ensure_clean_store(path, "w", **options) as store:
         store["obj"] = obj
@@ -490,7 +487,7 @@ def _check_roundtrip(obj, comparator, path, compression=False, **kwargs):
 def _check_roundtrip_table(obj, comparator, path, compression=False):
     options = {}
     if compression:
-        options["complib"] = _default_compressor
+        options["complib"] = "blosc"
 
     with ensure_clean_store(path, "w", **options) as store:
         store.put("obj", obj, format="table")

pandas/tests/io/pytables/test_store.py

@@ -30,8 +30,6 @@
     safe_close,
 )
 
-_default_compressor = "blosc"
-
 from pandas.io.pytables import (
     HDFStore,
     read_hdf,